As part of the continuous development of improvements made to all the constructional details which compose bicycles, the grip which forms the subject of the present invention arises in response to the need to simplify the manufacturing process and from requirements to improve their qualitative and operational characteristics.
The grips on the market nowadays generally differ from each other in terms of their particular anatomical shape, the materials used or the manufacturing process by means of which they are made.
As is known, said grips are traditionally formed by a substantially cylindrical body which is made of plastic material, is internally hollow and can be inserted onto the ends of handlebars generally formed by suitably shaped metal tubes.
Advantageously, grooves of varying shape may be formed on the outer surface of the grips, said grooves being intended to assist ventilation of the hand gripping thereon, preventing possible problems arising from excessive sweating.
The grip may also have a particular anatomical form able to allow an optimum grip by the cyclist and/or assist the natural blood circulation of the hand and/or produce a massaging effect on the palm.
In particular, said form may have a convexity arranged in the zone where the cyclist's hand rests, said convexity being capable of absorbing the vibrations transmitted from the ground. The shape and position of the abovementioned convexity are designed according to the position assumed by the cyclist on the bicycle, said position also depending, as is known, to a significant degree on the specific type of bicycle used. In fact, for example, general purpose bicycles, known as ATB tracking, presuppose that the cyclist assumes a sitting position able to determine a bust angle on the bicycle of about 60°, while mountain bikes (MTB racing) and city touring bicycles require a bust angle of about 30° and 90°, respectively.
In more recently manufactured grips, the anatomical form with anti-sweat grooves and the abovementioned convexity is obtained using relatively soft materials which have high shock-absorbency characteristics, such as rubber, soft plastic, polyurethane or, more advantageously, material in gel form.
Moreover, the same grips made of, or solely lined with, relatively soft materials are more easily subject to wear. The greatest deterioration occurs, as is known, at the ends and especially at the outermost end, which is easily able to come into contact with or scrape against other objects and which is often used to support the bicycle.
With the aim of limiting this drawback, grips provided with a protective plug mounted on the outer end of the handlebar have been recently developed as, for example, described and illustrated in U.S. Pat. No. 6,112,618. According to the embodiment shown in FIG. 2 of this patent, the gel grip is provided with an internal cavity intended to receive the handlebar tube. Alternatively, in the embodiment shown in FIG. 3, the gel part is designed in the form of a sleeve fixed externally on a main, rigid or semi-rigid, tubular-shaped body. In both cases, the plug is provided with a central projection intended to be inserted by force into the cavity of the handlebar so as to retain the grip in a fixed position.
In practice, however, both the embodiments shown in this patent do not allow a stable and easy engagement of the grip on the handlebar. It should be noted in particular that in the case where the grip is formed completely by material in gel form, it can be functionally difficult to fit the grip on the handlebar, given the significant friction which the gel material exerts on the metallic surface of the handlebar and which must be overcome during said insertion operation.
On the other hand, in the case where a rigid main body covered with a gel sleeve is envisaged, it is necessary to envisage a perfect calibration of the internal diameter of the main body and/or the external diameter of the handlebar so that the correct interference between said non-deformable elements results in a stable engagement of the grip on the handlebar. It is nonetheless clear that, in practice, it is not always possible to guarantee such machining precision and it is therefore convenient to assign the task of retaining the grip on the handlebar to the abovementioned central projection. In this case, however, the retaining force may be unsatisfactory given the small surface area available for retaining the grip. Moreover, projections of greater length would once again involve difficulties when inserting the grip on the handlebar.
Generally speaking, it can also be said that the grips manufactured to date are capable of exerting a stable fixing action only on handlebars with predetermined dimensions and adapt poorly to being mounted, with even minimum tolerances, on handlebars which diverge, even slightly, from said dimensions.
However, given that the handlebars available on the market, especially if derived from various manufacturing sources, may differ appreciably in terms of the size of their diameter, the result is that the grips are not generally capable of guaranteeing a stable fixing action on all handlebars.
It should also be remembered that the handlebars nowadays envisage a single protective element arranged on the outer end of the grip, while the inner end of said grip, which is intended to be inserted on the handlebar, is not protected in any way, with the result that said inner end is easily susceptible to rapid deterioration, especially where it is made of material which is soft and/or in gel form.